Advisory group disagrees with public on Burnside Bridge replacement design

PORTLAND, Ore. (KOIN) — After surveying nearly 20,000 citizens to learn which Burnside Bridge replacement design the public preferred most, Multnomah County was advised on Sept. 3 to move forward with a design that would defy public opinion.

It was recommended Tuesday that the Multnomah County Board of Commissioners choose the inverted Y-shaped cable-stay design for the Burnside Bridge replacement project. The inverted Y-shaped tower ranked fourth out of six designs presented to the public, survey results show. 

The recommendation was presented to the board of commissioners by the Community Design Advisory Group — a board of 20 volunteers tasked with reviewing information and public feedback related to the possible designs and presenting commissioners with a final suggestion. Advisory group member Brian Kimura told the board of commissioners Tuesday that, although the public's perspective played a significant role in the advisory group’s discussions, the group felt that it was better informed to make the right decision.

“After studying materials and attending 10 detailed meetings, our committee developed a deep understanding of the bridge options,” Kimura said. “While the public could access the information online, it would take approximately 30 hours to match our knowledge. Our recommendation of the inverted Y-scheme is grounded in objective reasoning and facts, whereas much of the public commentary was perceived as subjective opinion.”

In July, citizens were presented with two possible bridge types and six design options for the project. The survey gave respondents the ability to choose between a cable-stay tower or tied-arch design, each of which had three possible sub-designs.

According to the report presented to the Board of Commissioners Tuesday, 54.6% of people who responded to the survey said they preferred a tied-arch bridge type to a cable-stay tower. While most respondents said they preferred an arch design, the most popular of the six sub-designs was the V-shaped cable bridge. In the survey, 3,382 people listed the V-tower as their first choice. Another 3,352 people selected the braced basket-handle arch as their favorite. The third-most-popular design was the unbraced vertical arch. None of these options were recommended by the advisory group.

During the meeting, county officials like Commissioner Sharon Meieran repeatedly praised the county’s efforts to get the public involved in the decision making process. However, commissioners said very little about the advisory group’s decision to skirt public opinion. 

“Tremendous results from that survey,” Meieran said. “Those are really incredible numbers compared to what one usually gets in public surveys.”

Roughly 75% of the 19,234 people who responded to the survey said they were Multnomah County residents. Multnomah County Transportation spokesperson Sarah Hurwitz said that the number of younger residents who responded to the survey was “encouraging.”

“Twenty-nine percent of respondents were between the ages of 35 and 44,” Hurwitz said. “This was encouraging because, historically, older populations tend to respond to these types of infrastructure surveys.”

Of the people surveyed, another 25% said they were between the ages of 25 and 34 and 19% said they were 19 or younger. While the County generated an impressive level of civic engagement for the project, Community Design Advisory Group member Susan Lindsay, who, voted in opposition to committee’s recommendation, said that public opinion wasn't a big enough factor in the group's decision.

“I felt that the public’s input, gathered from an impressive outreach effort by the county and the consultants, represented more than simply another data point,” Lindsay said. “I felt it mattered strongly. At least more strongly than I witnessed being ultimately represented by the committee presentations and decision.”

Advisory group member Guenevere Millius gave several reasons as to why the group chose a bridge design that did not match the public’s preference. The group's reasoning included aesthetic, safety and maintenance concerns.

“Arch structures are easy to climb,” Millius said. “Burnside’s arches would be 8 to 9 feet across, creating a tempting walkway for intrepid interlopers. The conceptual drawings don’t show the large, potentially obtrusive structures necessary to prevent climbing. By contrast the cable-stay options will be much harder to climb and will prevent less need for deterrents.”

A cable bridge would also present fewer maintenance issues, the advisory group said. 

“We were told that rainwater running off these arches would have to be dealt with ‘very carefully’ to not stain structures underneath,” Millius said. “We are concerned that the systems necessary to pull rusty water away from the understructures could get lost in attempts to meet budget, leading to a potentially permanently-stained understructure.”

While the advisory group recommended that commissioners approve the inverted Y-shaped cable-stay design for the project, the board can still choose any of the six designs listed in the survey. The board will consider a resolution to adopt the bridge design on Sept. 12. The county said that it will have a better estimate of the cost of the chosen design by spring of 2025.

The County and other local agencies are rushing to replace the bridge with one that can withstand a Cascadia Subduction Zone earthquake. Scientists predict there is a 37% chance that a megathrust earthquake of 7.1 magnitude or greater will occur along the Cascadia Subduction Zone within the next 50 years.